如何求卡特兰数——代码如下

void catalan() //求卡特兰数

{

    int i, j, len, carry, temp;

    a[1][0] = b[1] = 1;

    len = 1;

    for(i = 2; i <= 100; i++)

    {

        for(j = 0; j < len; j++) //乘法

            a[i][j] = a[i-1][j]*(4*(i-1)+2);

        carry = 0;

        for(j = 0; j < len; j++) //处理相乘结果

        {

            temp = a[i][j] + carry;

            a[i][j] = temp % 10;

            carry = temp / 10;

        }

        while(carry) //进位处理

        {

            a[i][len++] = carry % 10;

            carry /= 10;

        }

        carry = 0;

        for(j = len-1; j >= 0; j--) //除法

        {

            temp = carry*10 + a[i][j];

            a[i][j] = temp/(i+1);

            carry = temp%(i+1);

        }

        while(!a[i][len-1]) //高位零处理

            len --;

        b[i] = len;

    }

}